Lots of limits in aviation, and different types. There’s weather limits, limitations of aircraft design, legal limits, even speed limits. (Yes, in certain places there are speed limits in the sky, though even those don’t apply if your aircraft stalls at a high enough airspeed.) And then there are personal limits.
Things like weather limits are easy to define, though not always so easy to implement. Stay five hundred feet from clouds vertically, and one thousand horizontally. Okay. *Gets in the plane.* Okay, there’s a cloud, how far away is it? Am I five hundred feet above it? (Is my instructor on board? No?) Sure, I’m callin’ that five hundred feet. Visibility can be easier to judge around Manitoba at least, since all the roads in southern Manitoba are mile roads, so you can just count how many roads away you can see to estimate visibility. But if it’s all trees, or water and lakes, you’re guessing.
Until you get into a control zone and they have terminal weather reports an tower control that can tell you the visibility is X. If you’re out busting VFR weather minimums, that’s generally when you’ll get caught, from what I understand.
Then there’s wind and crosswind – schools or anyone renting planes will have rules on how much wind you’re allowed to fly in. There will be a limit on wind in knots (usually twenty). And then a limit of gust factors – how much the wind is gusting up to – the low and high max. Gust factors of five of more take some special consideration when landing – you want to come in a little faster so that when the gusting disappears, you don’t suddenly find yourself near stall speed close to the ground.
Then there’s crosswind, and a school will usually give you a maximum crosswind factor you’re allowed to go out in. That’s, for the uninitiated, how much the wind is blowing across the runway. Obviously the easiest wind to land in, is a steady one, blowing straight at you, straight down the runway. The farther off the end of the runway the wind is originating, the trickier it is to deal with. Also, in a Pilot’s Operating Handbook, there will be a “demonstrated crosswind limit” which is basically what a test pilot has proven the plane can handle. It’s not a hard limit though. A good pilot may be able to land in a stronger crosswind than the POH has demonstrated if they know what they’re doing, and it’s not breaking any laws. Though it would likely be breaking school rules, if the pilot isn’t flying their own plane.
Of course, the wind can pick up and change while you’re flying, which is why you want to get a weather briefing if you’re going anywhere far from the airport. Getting a weather briefing is important. It’s just a quick phone call, and you have someone on the phone that really knows their shit. A lot of new students, me included, are shy about calling flight information services, and feel like they’re a bother. But having talked to them some, I know now, we’re not a bother at all, any more than when I’m at work (telephone tech support) and customers call saying “sorry to bother you, but…” No, people answering phones in a call center are paid to answer phones and give you information. They’re always happy to talk to me, and I can see why my instructor encouraged me to call them as often as I like.